--- linux-3.10/drivers/char/avm_new/generate-event-types
+++ linux-3.10/drivers/char/avm_new/generate-event-types
@@ -13,7 +13,7 @@
 
 (
 	: ${PERL5LIB:=}
-	export PERL5LIB="$PERL5LIB:${avm_dist_event}"
+	export PERL5LIB="${PERL5LIB:-}:${avm_dist_event}"
 
 	cd "${work}"
 	perl ${avm_dist_event}/avm_event_generate.pl 1>/dev/null 2>&1